Awareness is a relative concept. An animal may be partially aware, may be subconsciously aware, or may be acutely aware of an event. Awareness may be focused on an internal state, such as a visceral feeling, or on external events by way of sensory perception. Awareness provides the raw material from which animals develop qualia, or subjectiveideas about their experience.

Electro-chemical networks related to the chordatenervous system facilitate awareness. Researchers have debated what minimal components are necessary for animals to be aware of environmental stimulus, though all animals have some capacity for acute reactive behavior that implies a faculty for awareness.

Popular ideas about consciousness suggest the phenomenon describes a condition of being aware of one's awareness. Efforts to describe consciousness in neurological terms have focused on describing networks in the brain that develop awareness of the qualia developed by other networks.

When a patient goes for a surgical operation, it is desirable to temporarily make the patient unaware. Anaesthesiologists specialise in this and a major responsibility is prevent awareness during the operation. This is achieved by giving anesthetic drugs through the veins and through the lungs.